A comparison of mirex-induced liver growth to liver regeneration.

In intact rats given a single oral dose of mirex there was a dose-dependent increase in liver weight which peaked at 4 days. There were increases in hepatic RNA and protein, but DNA content per liver and DNA synthesis as measured by [3H]thymidine incorporation were unchanged. In partially hepatectomized rats dosed with mirex 24 h post-surgery, there was a dose-dependent increase in relative liver weight which peaked at 5 days. In partially hepatectomized rats simultaneously dosed with mirex, [3H]thymidine incorporation into DNA was unaltered. However, in rats dosed with mirex 24 h prior to partial hepatectomy, there was a 50% reduction in [3H]thymidine incorporation into hepatic DNA.